Mechanical counter having a positive shaft lock



April 1961 w. J. OPOCENSKY 2,980,327

MECHANICAL COUNTER HAVING A POSITIVE SHAFT LOCK Filed Jan. 5, 1959 FIG.I

IN VEN TOR.

WlLL RD OPOCENSKY Iii/w ATTORNEY United States.v

Willard J. Opocensky, Glendale, Calif., assignor to General Precision Inc., a corporation of Delaware Filed Jan. 5, 1959, Ser. No. 784,990

3 Claims. (Cl. 235-430) This invention relates to mechanical counters and more particularly to a novel positive shaft locking device for mechanical counters.

In certain types of mechanical counters, such as are used in computers, the counting dials are frictionally retained in position on their respective hubs by ball and detent connections. The hub carrying and driving the first, or at least significant, counter wheel is secured to a shaft and turns therewith. Subsequent counter dials and hub assemblies in the same bank are rotated by a transfer mechanism.

When it is desired to change the setting of the counting dials, a sharp pointed instrument is used to engage the unit order dial and rotate it to the desired position. The ball and detent connection allows relative movement between the dial and its respective hub. However, the friction of the ball and detent tends, during such setting, to cause rotation of the shaft, which is transferred into other components of the computer displacing them from correct position.

This invention overcomes the above condition by employing a positive locking means for the hub supporting shaft while adjusting the counter wheels thereon.

Briefly described, the illustrated embodiment of this invention comprises a counter having locking means associated with the hub of the uint order dial; the locking means being a pair of pivoted arms having serrations located on the inner surface of an arcuate recess complementary to the periphery of said hub which is provided with similar serrations. Means are provided for normally retaining the arms in a position in which they are out of engagement with the hub.

The accompanying drawing illustrates one form of this invention in which:

Figure 1 is a plan view, partially broken away, of a mechanical counter embodying a positive shaft locking device of my invention;

Figure 2 is a sectional view taken on the line 2-2 of Figure 1 showing the shafts in an unlocked position;

Figure 3 is a view similar to Figure 2 illustrating a locked position of the shafts; and

Figure 4 is a longitudinal sectional view taken on the line 4-4 of Figure 3.

Turning now to a detailed description of a counter embodying my invention and its shaft locking device, there is shown a mechanical counter having two banks of dials 10 and 12 rotatably mounted on shafts 14 and 16, respectively, and each journaled in a housing 13. A pair of shafts 20 and 22 support the transfer mechanisms. Electrical switch arms 24 are mounted on a pair of shafts 26 and 28 and are free to oscillate thereon. Shafts 26 and 28 are secured in. the housing .13. All of the foregoing is conventional.

Each bank of counter wheels 10 and 12 is provided with hubs 30 and 32 which are secured to their respective shafts 14 and 16 by pins 34 shown in Figures 3 and 4. Each stem of the hubs 30- and 32 is provided with spring pressed balls 36 which are adapted to engage detents 38 in counting dials 40. Each of the hubs 30 and 32 is provided with serrations on 42 on the periphery.

A pair of opposed levers 44 and 46 are mounted on the shafts 26 and 28, respectively, and are free to pivot thereon. Each of the levers 44 and 46 is provided with concave serrated surfaces 48 and 56 adapted to engage the serrations 42 on the hubs 3t) and 32. Each of the levers 44 and 46 is also provided with a pocket 52 to receive the opposite ends of a compression spring 54 which normally tends to keep the serrated surfaces 48 and 50 disengaged from the serrations 42 on the hubs 30 and 32. Each of the levers 44 and 46 is also provided with a frustoconical cavity 56 adapted to receive a free floating ball 58.

In the normal operating position, the levers 44 and 46 are disengaged by the action of the spring 54 pressing outwardly against the lower ends of the levers 44 and 46, pivoting them about the axis of shafts 26 and 28, cansing the upper ends of such levers to retract away from the hubs 30 and 32, and permits normal operation of the counter. When the levers 44 and 46 are in their inoperative position, the cavities 56 embrace the ball 58, under the pressure of spring 54, holding such levers in a neutral position preventing the levers 44 and 46 from dropping over against either of the hubs 36) or 32.

When it is desired to adjust the position of the counting dials 40, an instrument such as screw driver it? is inserted between the levers 44 and 46, forcing them apart to bring the concave serrated surfaces 48 and 50 into engagement with the serrations 42 on the hubs 3t} and 32, which prevents any movement thereof. Inasmuch as the counter wheels 30 and 32 are pinned to the shafts l4 and 16, both the hubs 3t) and 32 and shafts 14 and 16 are thereby positively locked in position preventing any rotation of these parts while the counting rings 40 are rotated to the desired position.

It is to be understood that modifications in size, shape, etc., of this locking means may be resorted to without departing from the spirit of my invention as set forth in the following claims.

I claim:

1. A mechanical counter comprising a pair of spaced hubs each mounted on a separate shaft and locked thereto, said hubs having serrations on the periphery thereof, a plurality of counting dials freely rotatably mounted on said shafts, a pair of positive shaft locking levers positioned between said spaced hubs, pivot means mounting each of said levers and resilient means urging said levers away from said hubs, said levers having concave portions with serrations thereon whereby said hubs and said shafts are positively locked against rotation when said levers are urged against said hubs permitting independent rotation of said counting dials.

2. A mechanical counter comprising a pair of spaced hubs each mounted on a separate shaft and locked thereto, said hubs having serrations on the periphery thereof, a pair of positive shaft locking levers positioned between said spaced hubs, pivot means mounting each of said levers, resilient means urging said levers away from said hubs and means on said levers to prevent said levers from pivoting together against one of said hubs when in an inoperative position, said levers having concave portions with serrations thereon whereby said hubs and said shafts are positively locked against rotation when said levers are urged against said counter wheels.

3. A mechanical counter comprising a pair of spaced hubs each mounted on a separate shaft and locked thereto, said hubs having serrations on the periphery thereof,

Patented Apr. 18, 1961'? a pair of positive shaft locking levers positioned between said spaced hubs, pivot means mounting each of said levers, resilient means urging said levers away from said hubs, each of said levers having a cavity therein and a free floating ball in said cavity adapted to prevent said levers from pivoting together against oneof said hubs when in an inoperative position, said levers having concave portions with serrations thereon whereby said hubs and said shafts are positively locked agianst rotation when said levers are urged against said counter wheels.

References Cited in the file of this patent UNITED STATES PATENTS Locher July 21, 1891 Phelps Dec. 24, 1889 Jordan Mar. 8, 1921 Jones Dec. 22, 1925 Miller Nov. 12, 1929 Lawrence June 16, 1936 Benjamin May 22, 1956 

